Radio antennas which are used in modern applications, such as frequency hopping systems, are often required to operate over a range of frequencies. Monopole antennas commonly employed on tactical applications typically are electrically short (have mechanical length less than one-quarter wavelength) and have highly reactive impedances at lower operating frequencies. These antennas may be greatly mismatched with the load impedance of an associated transmitter thereby leading to serious losses in transmission efficiency. To minimize transmission inefficiencies, antenna coupling systems employing tunable, high-voltage load coils (variable inductors) have been developed which resonate the capacitive reactance of the associated antenna when the antenna length is less than one-quarter wavelength at the operational frequency. Such coupling arrangements result in a high Q series resonant, high-voltage, narrow-band, tuned condition which must be adjusted for every change in frequency, in order to assure efficient power transfer to the antenna. High-voltage tuning inductors are rather expensive and relatively slow in executing the retuning function and accordingly may not provide an adequate solution to antenna tuning for applications such as frequency hopping systems.
One successful technique and apparatus for overcoming these problems is described and illustrated in U.S. Pat. No. 5,065,164, entitled "Frequency Range Enhanced Monopole Antenna," which issued on Nov. 12, 1991. This approach provides an electrically short tactical antenna system which has inherently broader bandwidth characteristics in radiating radio frequency energy and also simplifies antenna coupling requirements. While this previous implementation is a significant improvement over prior art antenna implementations, there continues to be a need for an antenna system having even greater frequency range operating capabilities and a simplistic coupler apparatus.